No abstract

Bill & Melinda Gates Foundation.

Hip and knee OA is one of the leading causes of global disability. Methodological issues within this study make it highly likely that the real burden of OA has been underestimated. With the aging and increasing obesity of the world's population, health professions need to prepare for a large increase in the demand for health services to treat hip and knee OA.

Worldwide, osteoarthritis (OA) is estimated to be the fourth leading cause of disability. Most of this disability burden is attributable to the involvement of the hips or the knees. OA is strongly associated with ageing and the Asian region is ageing rapidly. Further, OA has been associated with heavy physical occupational activity, a required livelihood for many people living in rural communities in developing countries. Unfortunately, joint replacement surgery, an effective intervention for people with severe OA involving the hips or knees, is inaccessible to most people in these regions. On the other hand, obesity, another major risk factor, may be less prevalent, although it is on the increase. Determining region-specific OA prevalence and risk factor profiles will provide important information for planning future cost-effective preventive strategies and health care services. An update of what is currently known about the prevalence of hip and knee OA from population-based studies conducted in the Asian region is presented in this review. Many of the recent studies have conducted comparisons between urban and rural areas and poor and affluent communities. The results of Asian-based studies evaluating risk factors from population-based cohorts or case-control studies, and the current evidence on OA morbidity burden in Asia is also outlined.

Internationally, prevalence estimates for osteoarthritis show wide variability depending on the age and sex of the studied population, the method of case identification used, and the specificity of joint sites included. Currently, there is no generally agreed "gold standard" for identifying cases of osteoarthritis in epidemiologic studies. Despite this lack of standardisation, it is consistently demonstrated in population-based studies, worldwide, that osteoarthritis prevalence is positively associated with increasing age and that the greatest disease burden is attributable to involvement of the hip or knee joints. To estimate the true burden of osteoarthritis involving the hips or knees, comprehensive accounting of all associated morbidity is required. The identification of modifiable risk factors for disease incidence and progression is needed.